CRP and appendicitis: We demonstrated that the patients had right lower quadrant (RLQ) abdominal pain that originated from causes other than appendicitis with diagnostic tests (alone or in combination) for diagnosing appendicitis, clinical signs (e.g., psoas sign, obturator sign, Rovsing sign, and McBurney sign), clinical symptoms (e.g., fever, migrating pain, and guarding), laboratory tests (e.g., white blood cell count, C-reactive protein concentration, and left shift), and imaging tests (e.g., abdominal X-ray; US; CT with or without contrast administered orally, rectally, or intravenously).